[pups] thrust meter?

[pups] thrust meter?

[Brian Knittel]

The thrust meter project -- was that an analog meter that displayed % 
CPU utilization? I remember that Tom Ferrin had one mounted in the 
middle of a DEC panel filler on the 11/70 at the Computer Graphics 
Lab at UCSF. It was really delightful having this analog meter 
bouncing up and down as people worked away.  

Brian


=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
_| _| _|  Brian Knittel
_| _| _|  Quarterbyte Systems, Inc.
_| _| _|  Tel:   1-510-559-7930
_| _| _|  Fax: 1-510-525-6889
_| _| _|  Email: brian at quarterbyte.com
_| _| _|  http://www.quarterbyte.com

[pups] thrust meter?

[Dave Horsfall]

On Wed, 4 Oct 2006, Brian Knittel wrote:

> The thrust meter project -- was that an analog meter that displayed % 
> CPU utilization? I remember that Tom Ferrin had one mounted in the 
> middle of a DEC panel filler on the 11/70 at the Computer Graphics Lab 
> at UCSF. It was really delightful having this analog meter bouncing up 
> and down as people worked away.

I believe so...

(Dave leans over to dig out article.)

OK, page 27 of AUUG Vol 2 No 5 (Jun/Jul 1980).

It integrated the BUS BUSY signal over a suitable time constant (and my 
electronics knowledge is a bit too rusty to figure out Tc, but with a 
10uF tantalum capacitor I imagine it would be a few seconds).

The credits are:

Designed originally by Pete Madams (Essex), modified by J Feenstra 
(Nijmegen), and this drawing executed by Paul Griffith (Essex).

-- Dave

[pups] thrust meter?

[John Holden]

On 05/10/2006, at 10:15 PM, Dave Horsfall wrote:

> On Wed, 4 Oct 2006, Brian Knittel wrote:
>
>> The thrust meter project -- was that an analog meter that displayed %
>> CPU utilization? I remember that Tom Ferrin had one mounted in the
>> middle of a DEC panel filler on the 11/70 at the Computer Graphics  
>> Lab
>> at UCSF. It was really delightful having this analog meter  
>> bouncing up
>> and down as people worked away.
>
> It integrated the BUS BUSY signal over a suitable time constant  
> (and my
> electronics knowledge is a bit too rusty to figure out Tc, but with a
> 10uF tantalum capacitor I imagine it would be a few seconds).

Um, depends what you mean by thrust. It was originally designed for a  
11/45
where bus activity would have been a fare indication of machine load  
since
all memory and i/o used the unibus (I'm excluding the effects of fastbus
memory on 11/50 and 55's).

The 11/70 unibus was actually slower than the 11/45, and generally  
didn't
have memory or disk/tape i/o on it (separate memory bus and massbus). So
'thrust' was probably mainly character i/o (dh and dz's) and older
disk/tapes (RK05's etc)

Now, where's 11/70 maintenance printset?

Cheers
John

[pups] thrust meter?

[Johnny Billquist]

John Holden wrote:
> On 05/10/2006, at 10:15 PM, Dave Horsfall wrote:
> 
>>On Wed, 4 Oct 2006, Brian Knittel wrote:
>>
>>>The thrust meter project -- was that an analog meter that displayed %
>>>CPU utilization? I remember that Tom Ferrin had one mounted in the
>>>middle of a DEC panel filler on the 11/70 at the Computer Graphics  
>>>Lab
>>>at UCSF. It was really delightful having this analog meter  
>>>bouncing up
>>>and down as people worked away.
>>
>>It integrated the BUS BUSY signal over a suitable time constant  
>>(and my
>>electronics knowledge is a bit too rusty to figure out Tc, but with a
>>10uF tantalum capacitor I imagine it would be a few seconds).
> 
> Um, depends what you mean by thrust. It was originally designed for a  
> 11/45
> where bus activity would have been a fare indication of machine load  
> since
> all memory and i/o used the unibus (I'm excluding the effects of fastbus
> memory on 11/50 and 55's).
> 
> The 11/70 unibus was actually slower than the 11/45, and generally  
> didn't
> have memory or disk/tape i/o on it (separate memory bus and massbus). So
> 'thrust' was probably mainly character i/o (dh and dz's) and older
> disk/tapes (RK05's etc)
> 
> Now, where's 11/70 maintenance printset?

I got them here. :-)

Hmm, but yeah. Since the bus might be idle even though the CPU is 
running, you might not get a very good reading by looking at the unibus.
But I think there are other signals that would be better to integrate 
over. Such as the MASTER lamp (or is it the CPU lamp perhaps?) of the 
front panel.

	Johnny

[pups] thrust meter?

[Dave Horsfall]

On Tue, 10 Oct 2006, Johnny Billquist wrote:

> Hmm, but yeah. Since the bus might be idle even though the CPU is 
> running, you might not get a very good reading by looking at the unibus. 
> But I think there are other signals that would be better to integrate 
> over. Such as the MASTER lamp (or is it the CPU lamp perhaps?) of the 
> front panel.

Which reminds me; try holding the light-pen of a GT40 against its own 
console lights :-)

-- Dave

[pups] thrust meter?

[John Holden]

On 10/10/2006, at 9:00 PM, Dave Horsfall wrote:

> On Tue, 10 Oct 2006, Johnny Billquist wrote:
>
>> Hmm, but yeah. Since the bus might be idle even though the CPU is
>> running, you might not get a very good reading by looking at the  
>> unibus.
>> But I think there are other signals that would be better to integrate
>> over. Such as the MASTER lamp (or is it the CPU lamp perhaps?) of the
>> front panel.
>

The MASTER lamp signifies that the CPU has the unibus, hence a  
similar problem
to using BUS BUSY. You could use KERNEL/SUPERVISOR/USER signals as an  
indication
of context switches. My favourite is a light chaser using the data  
display from
the idle loop. Only works on an 11/45/50/55/60/70 (a bit boring on a  
11/60 as
it had a 7 segment display).

> Which reminds me; try holding the light-pen of a GT40 against its own
> console lights :-)
>

Got one in my office. The lightpen latches the current x/y  
coordinates from
the d/a converters. Aim it at something that will trigger it and you  
get random
hits all over the screen

[pups] thrust meter?

[Dave Horsfall]

On Tue, 10 Oct 2006, John Holden wrote:

> Um, depends what you mean by thrust. It was originally designed for a 
> 11/45 where bus activity would have been a fare indication of machine 
> load since all memory and i/o used the unibus (I'm excluding the effects 
> of fastbus memory on 11/50 and 55's).

According to the article, it was indeed for the 11/45.

-- Dave